A known door lock operation apparatus for a vehicle which performs a locking operation by rotating an output shaft of an actuator in a normal direction and an unlocking operation by rotating the output shaft in a reverse direction is disclosed in JP62-197583A. A known door closing apparatus for a vehicle is disclosed in JP2007-2589A, which performs a closing operation, capturing a striker by rotating a latch by displacing, in one direction, a driven gear serving as a displacement body which receives a motor driven force and is rotatable in normal and reverse directions. The door closing apparatus further performs a releasing operation in which a pawl is rotated to disengage the latch and the pawl by displacing the driven gear in the other direction.
The known apparatuses explained above includes a releasing function which disengages the latch and the striker by displacing the displacement body such as a sector gear which receives the motor driven force in a releasing direction with reference to a neutral region and a closing function in which the latch captures the striker by actuating the displacement body in a closing direction with reference to the neutral region. In those circumstances, in case of displacing the displacement body to the neutral region by the motor driven force after executing the releasing function or the closing function, a neutral detection portion such as a switch, in order to control for stopping the motor, is required. However, in the event that the neutral detection portion is in failure, there is a possibility that the displacement body may be moved to a terminal end of the displacement. In other words, the movement of the displacement body is not stopped after the execution of the closing operation, and starting the releasing operation to re-unlock the once locked door. Further, there is also a possibility that the movement of the displacement body is not stopped within the neutral region after the execution of the releasing operation, and starting the closing operation thus to re-lock the once unlocked door.
A need thus exists for a door opening and closing apparatus for a vehicle which is not susceptible to the drawback mentioned above.